Epidemiological characteristics and factors influencing clinical severity of repeated novel coronavirus infections in Harbin
哈尔滨市新型冠状病毒重复感染者流行特征及临床严重程度影响因素分析

摘要

目的 为明确哈尔滨新型冠状病毒感染的重复感染流行特征、康复进程以及影响重复感染病例临床严重程度的相关因素，为疫情防控政策的制定提供科学依据。方法 分析2023年5月-2024年10月哈尔滨市新冠病毒二次感染病例个案数据，探讨其流行特征。随机选取200例二次新冠病毒感染病例及无症状感染者进行个案调查，采用χ2检验、logistic回归模型方法分析重复感染临床型别的影响因素。结果 2023年5月-2024年10月哈尔滨市新冠病毒二次重复感染占比为16.86%，女性重复感染高于男性（χ²=61.781，P<0.001）；3岁以下人群重复感染最低（0.52%），而60-79岁组老年人群重复感染最高（35.34%）。与首次感染相比，二次感染的康复时间明显缩短（χ²=91.864，P<0.001）。有既往病史的无症状感染者和轻型男性病例在重复感染中表现出较低的临床严重程度。结论 本研究哈尔滨新冠病毒二次感染占比整体较低，二次感染的临床严重程度有所减轻，且康复周期缩短。在以后的防控工作中，须重视女性高龄人群的重复感染。

Abstract

Objective To elucidate the epidemiological characteristics of repeated infections with novel coronavirus (COVID-19) in Harbin, the recovery process, and the related factors influencing the clinical severity of repeated infections, providing a scientific basis for formulating epidemic prevention and control policies in the new stage.
Methods Case data of secondary infections with SARS-CoV-2 in Harbin from May 2023 to October 2024 were analyzed to explore their epidemiological characteristics. A total of 200 cases of secondary COVID-19 infections and asymptomatic infected individuals were randomly selected for case investigation. The χ² test and logistic regression model were used to analyze the influencing factors of clinical manifestations in repeated infections.
Results From May 2023 to October 2024, the proportion of secondary COVID-19 infections in Harbin was 16.86%. The rate of repeated infections was higher in females than in males (χ²=61.781, P<0.001). The lowest rate of repeated infections was observed in individuals under 3 years old (0.52%), while the highest rate was in the elderly population aged 60-79 years (35.34%). Compared with the first infection, the recovery time for secondary infections was significantly shortened (χ²=91.864, P<0.001). Asymptomatic infected individuals with a history of previous illness and male patients with mild symptoms exhibited lower clinical severity during repeated infections.
Conclusion   In this study, the overall proportion of secondary COVID-19 infections in Harbin was relatively low. The clinical severity of secondary infections was reduced, and the recovery period was shortened. In future prevention and control efforts, attention must be paid to repeated infections in elderly female populations.